The Microbial World: The Nitrogen Cycle Explained

Life on earth would not be as it is today if it was not for the element of nitrogen. All living things count on nitrogen to survive and to be in existence. The importance of this element for plants and animals is that they need nitrogen to activate their growth cells and to aid in reproduction. Nitrogen is always moving in a constant motion, going from the air to the ground and then into plants and animals. In order for the plants and animals to benefit from nitrogen, its characteristics will change into compounds that can be absorbed into the ground, supplying the soil with the right balance of nitrogen that will feed plants and animals.

Nitrogen Fixation

Nitrogen in itself is a molecule composed of proteins, amino acids and other substances. However, this molecule must alter its form so that living organisms will absorb its nutrients. When changing to other essential components that are compatible with plants and animals, the process of nitrogen fixation will take place. The new and altered form becomes “fixed” with ammonium and ions that benefit the growth process in living things.

Assimilation

Nitrogen comes from both organic and inorganic substances with the purpose of converting it into ammonia and amino acid. The process of assimilation is where plants and animals take in these newly converted substances. For plants, the ammonia and amino acid is absorbed through the roots, turning the substance into protein and nucleic acids. Animals then benefit from this process by eating the plants.

Ammonification

The process of ammonification is another phase of the nitrogen cycle. It converts the organic forms of nitrogen into ammonium. Organic forms of nitrogen are found in the remains of dead plants, animals and in the soil. When these things die and go through the process of decomposing, ammonification takes place, turning microorganisms into ammonia. When there is no oxygen present, the decomposed material will become foul smelling because of putrefactive elements. However, through the ammonification process, the stench causing organisms will change into ammonia.

Nitrification

The nitrification process begins with the conversion of ammonia, turning it into nitrates. This process usually takes place in the environment with the help of bacteria. The two types of bacteria used in the nitrification process are the nitrosomonas and the nitrobacters. The nitrobacters start the nitrification process by creating nitrites, and then the nitrobacters take those nitrites and turn them into nitrates. When this occurs, it causes natural chemical reactions to take place.

Denitrification

This phase involves turning nitrates into nitrite, nitrous oxide and ammonia. This happens with the helps of denitrifying bacteria, which does not use oxygen in completing this phase. An example of this taking place is the aftermath of a flood. Water covering the soil will make it impossible to get oxygen from the air to that soil. When oxygen is not accessible, dentrification takes place and organisms then die and deteriorate.

Anaerobic Ammonium Oxidation

The purpose of anaerobic annomium oxidation is to change ammonium and nitrite into dinitrogen gas. This phase is referred to as anammox. One of the main places that this process takes place is through the marine nitrogen cycle. The process produces 50% of all dinitrogen gas that is in the oceans. With this application used in wastewater treatment, it will remove unwanted ammonium.

Although the nitrogen cycle is a natural occurrence that takes place, man has disrupted the normal order of this cycle. People, through their scientific inventions have increased the amount of nitrogen that is on land. Much of this increase comes from using fertilizers that are laced with nitrogen. On one hand, the extra dose of nitrogen is good for plant growth, but at the same time, it is interfering with the typical order of the ecosystems. These manufactured inventions are actually causing negative issues in climate change, as well as in the health scope of human beings. This shows that change is not necessarily beneficial when it disrupts the natural order of things.